Digital camera modules are currently being incorporated into a variety of host devices such as, for example, cellular telephones, personal data assistants (PDSs), computers, etc. Such host devices are becoming increasingly more compact and, therefore, permitting less and less space for camera module form factors. Accordingly, host device manufacturers prefer digital camera modules to be small, so that they can be incorporated into the host device without increasing the overall size of the host device. Of course, host device manufacturers also prefer camera modules that capture images of the highest possible quality. Therefore, the goal in designing and manufacturing camera modules is to minimize size and maximize image quality capabilities.
A conventional digital camera module generally includes an integrated image capture device (ICD), passive components, a printed circuit board (PCB), an autofocus actuator, a lens, and a housing. Typically, the ICD, passive components, and autofocus actuator are mounted on the top of PCB. Further, the lens is coupled to the autofocus actuator and the housing is attached to the PCB so that ICD, passive components, and autofocus actuator are covered by the bottom of the housing. The top of the housing typically includes an optical opening that exposes the lens. The bottom surface of the PCB typically includes a plurality of electrical contacts that provide a means for electrically connecting the camera module to a host device.
One problem with conventional camera module designs is that they have a relatively large footprint and, therefore, occupy a significant amount of real-estate area on the host device. This is because the housing has to be large enough to cover the image sensor, the electrical components, the autofocus actuator, and the lens.
Another problem is that conventional camera modules have an overall complex assembly and mechanical stack-up of components which, consequently, lead to other problems. For example, the high overall height of conventional camera modules limits how thin the host devices can be made. As another example, the lens is indirectly coupled to the image sensor through a stack-up of several intermediate components such that an undesirable amount of optical tilt may exist in the camera module. Of course, optical tilt between the lens and the image sensor is a well known problem that is extremely difficult to minimize and can substantially reduce the image quality of a camera module. As another example, the design stage for conventional camera modules is long because it requires arranging multiple electrical components (e.g., IC chips, resistors, capacitors, etc.) on a substrate that has limited available real estate.
It is against this background that a simplified camera module design has been developed, specifically a shorter camera module that reduces optical tilt.